My sister has recently developed some odd red spots on her chest, so I thought I'd ask here if anyone knew what this was.

These are flat spots. They are on the part of her chest under her neck that is usually exposed, not covered with clothing. Don't know if that makes a difference.

These are not raised spots. They are flat. Just dark red color like blood under the skin. They go away, but others appear. Each spot is small, about 1/8 inch. Has been going on for a few months. Don't itch or anything, just look odd.

These red spots are easy to remove, usually in one treatment, with laser treatments. They are just a change in melanin and pigmentation of the skin, but if they concern you a laser treatments will make them disapear entirely. The versapulse laser is perfect for eliminating hyperpigmentation.